A 0.176 mol sample of Kr gas is contained in a 8.00 L flask at room temperature and pressure. What is the density of the gas, in grams/liter, under these conditions?

Feb 23, 2018

$\rho = 1.84 g \textcolor{w h i t e}{l} {L}^{-} 1$

Explanation:

First, we need to find the mass of $\text{Kr}$ by using the equation:

$\frac{m}{M} _ r = n$, where:

• $m$ = mass ($g$)
• ${M}_{r}$ = molar mass ($g \textcolor{w h i t e}{l} m o {l}^{-} 1$)
• $n$ = number of moles ($m o l$)

$m = n {M}_{r}$

$m \left(\text{Kr")=n("Kr")M_r("Kr}\right) = 0.176 \cdot 83.8 = 14.7488 g$

$\rho = \frac{m}{V} = \frac{14.7488}{8} = 1.8436 \approx 1.84 g \textcolor{w h i t e}{l} {L}^{-} 1$